Solar control films are used in automotive window glass and other vehicular glazing to reduce solar heat gain, interior temperatures and air conditioning loads. Commercially available solar control films include XIR™-70, XIR-75, V-KOOL™ and Hüper Optik™ films from Southwall Corporation, ULTRA PERFORMANCE™ 75 film from Bekaert Specialty Films, LLC, S-LEC™ sound and solar film from Sekisui Chemical Co., Ltd. and various films from CPFilms Inc. Coated glass products with solar control features include SUNGATET™ windshields from PPG Industries, Inc. and SOLARSHIELD™ glass from AFG Industries, Inc. These film and coated glass products are intended to reject or absorb infrared (or in some cases ultraviolet) energy while transmitting visible light. Unfortunately, good infrared rejection and good visible transparency are inversely related. It can be difficult to obtain desired solar control levels while still satisfying applicable visible light transparency (Tvis) requirements. For example, European Standard ECE R-43 requires a Tvis of at least 75% for windshields and at least 70% for sidelights and backlights. U.S. Federal Motor Vehicle Safety Standard 205 (49 C.F.R Part 571.205), SAE ANSI Z26.1-1996 and Japanese Standard JIS Safety Regulations for Road Vehicles, Article 29 require a Tvis of at least 70% for motor vehicle glazing.
There remains a need for solar control films having high visible light transmission and good solar control characteristics.